The present invention was developed for use with an overedge sewing machine but could be used with any type of machine in which a chain is produced after the completion of a seam; and, it is desired to cut the chain, retain the cut end of the chain that leads back to the needle and to sew the retained chain end into the next seam.
A device carried by the presser foot of a sewing machine for severing a chain of stitches extending between a sewn workpiece and the needle of the machine, retaining the severed end of the chain that extends from the needle and guiding the retained chain such that it is incorporated into the seam of stitches formed in the following workpiece is shown in U.S. Pat. No. 4,040,370. The device of this prior art patent is difficult for an operator to use and thus requires a relatively long time period to complete the operation. In this prior art device, after completing a stitching operation on a workpiece, the operator must slide the sewn workpiece along the bevel 23 and must then cause the chain to enter the slot 16. The patent implies that the bevel 23 in some way assists the operator in causing the chain to enter the slot 16; however, the patent does not explain how this assistance is provided. The bevel 23 is parallel to slot 16 and it is apparent that after the operator slides the workpiece along bevel 23, the operator must then reverse the direction of the workpiece a full 180.degree. and index it to the side if the chain is to enter the slot 16. After getting the chain to the slot 16, the operator must then insert the chain beneath the leaf spring 19 which grips the chain. The portion of the chain that extends from where it is gripped by leaf spring 19 to the workpiece is then drawn by the operator toward the blade 21 where it is cut. Thus, the operator must manipulate the workpiece and connected chain in a stop and start maze-like pattern to complete the desired operation.
Not only is the use of this prior art device time consuming it is not ergonomically sound. Commercial sewing machine operators perform operations such as cutting a stitch chain and incorporating the retained chain in the next seam thousands of times in an eight hour work day. When the pattern of movement that an operator's hand must follow to perform the task is awkward and tortious as it is in the above prior art device, it can result in physical problems, such as carpal tunnel syndrome, to the operator who must perform the operation thousands of times each work day.
The thread used to produce the chain between successive workpieces is wasted material and thus cost savings can be realized by minimizing the length of chain. The commercially available devices that are available to cut the chain and retain the cut end so that it can be sewn into the next seam require relatively long chain lengths and thus add unnecessary cost to the finished product.
For the foregoing reasons there is a need for an ergonomically sound apparatus that will allow a sewing machine operator to produce a relatively short stitch chain at the end of a seam and in a single smooth motion cause the chain to be severed and the end of the chain that extends from the needle retained and guided into the next seam.